The Medical Illness Counseling Center (MICC) shall support the research effort of the HIV and AIDS Malignancy Branch (HAMB) in the Division of Clinical Sciences, National Cancer Institute by assessing, through longitudinal studies using psychometric testing and neuropsychological evaluation, the status of psychological abnormalities and developmental progress in behavior, cognition, and motor abilities of adults and children with chronic medical illness, such as HIV disease and cancer. They will investigate the effect of appropriate treatments on these psychological functions. MICC shall provide comprehensive, state of the art neuropsychological and behavioral evaluations of pediatric and adult HAMB patients with HIV infection and possibly other NIH patients with HIV and/or cancer. The comprehensive evaluations shall include an assessment of the following domains of function: General Intelligence, language, visual spatial, perceptual, and constructive abilities, attention and concentration, concept formation and judgment, motor strength and speed, executive function, adaptive behavior, learning and memory. MICC shall develop, based on existing data, comprehensive and monitoring batteries of neurocognitive functions that are sensitive to disease specific effects on the CNS and to changes with therapy or disease progression. They shall provide neurobehavioral measures through appropriate assessments to further investigate the pathogenesis of the encephalopathy, dementia, or the neuropsychological abnormalities in these patients. This may include exploring relations between neurobehavioral measures and immunological, hematological, virological, neurological (brain imaging studies), genetic, biochemical and physiological variables.